Knowledge Bank

Fluorescence spectra of gaseous MgO induced by $Ar+$ laser-innes have been studied, MgO was generated by the reaction between magnesium vapor and $N2$O. The laser coincidences in the $B^{1}\Sigma^{+} - $X$^{1}\Sigma^{+}$ band system are the following. a) 4765 {\AA} line: R(26) of the 5-4 band, R(49) of the 4-3 band, and R(70) of the 3-2 band, all with $\mathrm{<mrow\; data-mjx-texclass="ORD">24</mrow>}MgO$.b) 4965 {\AA} line: R(36) of the 2-2 band of $\mathrm{<mrow\; data-mjx-texclass="ORD">26</mrow>}MgO$.c) 5145 {\AA} line: P(10) of the 4-5 band of $\mathrm{<mrow\; data-mjx-texclass="ORD">24</mrow>}MgO$, R(25)of the 3-4 band of $\mathrm{<mrow\; data-mjx-texclass="ORD">26</mrow>}MgO$, R(50) of the 2-3 band of $\mathrm{<mrow\; data-mjx-texclass="ORD">25</mrow>}MgO$, and R(70) of the 1-2 band of $\mathrm{<mrow\; data-mjx-texclass="ORD">24</mrow>}MgO$. Each B-X excitation, in general, gives rise to band progressions extending to hither vibrational levels of both the $X1\Sigma +$ and the $A1\Pi$ state that have not been rotationally analysed. Perturbations in the $X1\Sigma +$ and the $A1\Pi$ state have been discovered. The former is believed to be due to the lowest $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Pi$ state. Perturbation-induced $B1\Sigma +-3\Pi$ transitions (10 lines) which accompany the strongly perturbed lines have been confirmed, thus allowing the first observation of the lowest $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Pi$ state. Calculations are in progress to determine the spectroscopic constants, the spin-orbit coupling constants and the perturbation matrix clement of the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Pi$ state, but the preliminary treatment places its potential bottom $\sim 900cm-1$ below the $A1\Pi$ state- This result will facilitate the future analysis of the B-X band system with $v>2$. Population of the A-state molecules $(Te=3563cm-1)$ in the flame has been detected through fluorescences induced by a tunable dye laser (Rhodamine 6G) and It confirmed the symmetry of the A-state as $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Pi$